1. Field of the Invention
The present invention generally relates to a fuel reformer for mounting on a vehicle and more particularly to a reformer for mounting on a vehicle for reforming hydrocarbon fuel to a hydrogen-containing gas using water vapor.
2. Description of the Prior Art
Conventionally, it has been proposed to use a type of fuel reformer for mounting on a vehicle which performs a reforming reaction by causing raw material gas to flow in a vertical direction (for example, refer to Japanese Patent Laid-Open Publication No. Hei 4-200737). In this apparatus, the reforming reaction is performed by spirally wrapping two plate members around a vertically standing, cylindrically-shaped housing to form a catalyst layer and making the raw material gas flow vertically. The fuel reformer is provided around the center of a vehicle, on the left side or on the right side.
However, this type of reformer suffers in that the reformer is not suitable for mounting on a vehicle, especially a small passenger car. In a typical small passenger car, the passenger compartment is provided at the center of the vehicle and the driving devices for the vehicle, including the fuel reformer, are provided in the front or rear side. Thus, if the fuel reformer is vertically provided at the center, it would occupy a portion of the passenger compartment, which forces the passenger compartment to be smaller and in some cases, blocks the driver""s field of view. Moreover, because the fuel reformer is generally operated at a high temperature (more than 300xc2x0 C.), care must be taken so that this heat does not affect the passenger compartment. In a typical vehicle, the horizontal dimension (front/rear direction and right/left direction) of the vehicle is greater than the vertical dimension of the vehicle. When the reforming reaction is performed by making the raw material gas flow vertically, in some cases, contact time of sufficient length for contact between gas and the catalyst cannot be obtained, resulting in inadequate reforming performance.
When any apparatus, including, but not limited to, a fuel reformer, is mounted on a vehicle, various constraints are generated because space in the vehicle is limited and each space plays a particular role. Due to these constraints, some problems arise that are not applicable when the apparatus is not mounted on a vehicle.
One object of a fuel reformer for mounting on a vehicle according to the present invention is to solve the problems generated when the apparatus is mounted on a vehicle. In other words, some of the objects include, placing a fuel reformer at a suitable space in a vehicle, reducing the size of the fuel reformer for placing it in the limited space, improving fuel reforming efficiency in the fuel reformer, improving ease of maintenance of the fuel reformer, facilitating replacement of each section of the fuel reformer, and simplifying the structure of the fuel reformer.
In order to achieve at least some of the above mentioned objects, the fuel reformer for mounting on a vehicle according to the present invention employs the following.
According to one aspect of the present invention, a fuel reformer for mounting on a vehicle comprises a vaporization section for vaporizing reforming raw material containing hydrocarbon fuel and water, a reforming section for reforming the raw material gas containing the vaporized reforming raw material by a reforming reaction to obtain hydrogen-rich reformed gas, and a carbon monoxide reducing section for reducing the carbon monoxide concentration within the reformed gas to obtain fuel gas, wherein the reformer performs the reforming reaction by making the raw material gas flow in a direction approximately parallel to the floor surface of the vehicle.
In accordance with this aspect of the present invention, by making the material gas flow in a direction approximately parallel to the floor surface of the vehicle for the reforming reaction, the fuel reformer for mounting on a vehicle becomes more suitable for mounting on a vehicle which has a larger degree of freedom in the horizontal direction than in the vertical direction. That is, when the reformer is mounted on a vehicle having its parallel dimension larger than its vertical direction, such as a small passenger car, a reaction container (catalyst layer) can be extended so that there is a sufficiently long contact time between the raw material gas and the catalyst. As a result, the performance of the fuel reformer can be improved.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the carbon monoxide reducing section can be constructed so that the carbon monoxide concentration within the reformed gas is reduced by making the reformed gas flow in a direction approximately parallel to the floor surface of the vehicle. In this manner, by reducing the carbon monoxide concentration by making the reformed gas flow in a direction approximately parallel to the floor surface of the vehicle, the apparatus becomes more suitable for mounting on a vehicle having a larger degree of freedom in the horizontal direction than in the vertical direction. Moreover, because the reformed gas can contact the catalyst for a sufficiently long period of time, fuel gas with significantly reduced carbon monoxide concentration can be obtained.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section can be constructed so that the reforming raw material is vaporized by causing the reforming raw material to flow in a direction different from the direction of the raw material gas in the reforming section. In this aspect of the present invention, the different direction can be a direction approximately orthogonal.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section, the reforming section, and the carbon monoxide reducing section can be provided sequentially in that order with at least one bending section which bends at a predetermined angle. In this manner, the reformer can be placed in a limited space of a vehicle. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the predetermined angle can be approximately 180 degrees. Moreover, in this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming section can be divided into a front side and a rear side with the bending section provided between the front and rear sides of the reforming section, or, alternately, two bending sections can be provided, one between the vaporization section and the reforming section and the other between the reforming section and the carbon monoxide reducing section. According to this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section and the carbon monoxide reducing section can be provided adjacent to each other. In this manner, by placing the vaporization section and the carbon monoxide reducing section adjacent to each other for heating the reforming raw material to be supplied to the vaporization section at the carbon monoxide reducing section, heating efficiency can be improved.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the carbon monoxide reducing section can be configured to heat the reforming raw material before the reforming raw material is supplied to the vaporization section using heat generated by the reduction of carbon monoxide. In this manner, the reforming raw material can be heated while the carbon monoxide reducing section is cooled, and energy efficiency can thus be improved. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the carbon monoxide reduction section can be configured to heat the reforming raw material by making the reforming raw material flow in a direction approximately perpendicular to the flow of the reformed gas. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the carbon monoxide reducing section can be formed to have an approximate rectangular prism shape.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section can be configured to vaporize the reforming raw material by heat exchange with a combustion gas flowing through a combustion catalyst layer carrying combustion catalysts for combusting fuel. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section can be configured to vaporize the reforming raw material by making the reforming raw material flow in a direction approximately perpendicular to the flow of the fuel and the combustion gas. In this aspect of fuel reformer for mounting on a vehicle according to the present invention, the vaporization section can be provided with the combustion catalyst layer in a portion of a folded flow path. In this manner, the heat exchange efficiency can be improved. In these aspects of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section can be constructed in an approximate rectangular prism shape. In an aspect of the fuel reformer for mounting on a vehicle according to the present invention where the reforming raw material is vaporized by heat exchange with the combustion gas, the fuel reformer can further comprise a combustion gas temperature detector for detecting the temperature of the combustion gas and first vaporization control means for controlling operation of the vaporization section so that the detected temperature of the combustion gas is at a target temperature, preset for the combustion gas. In this manner, the combustion gas can be controlled to be at the target temperature. The target temperature is determined from the type of reforming raw material used in the fuel reformer and operational condition of the fuel reformer, etc.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the fuel reformer can further comprise a first oxygen-containing gas supplier for supplying oxygen-containing gas to the reforming raw material vaporized at the vaporization section so that the raw material gas is obtained. With this configuration, a portion of hydrocarbon fuel contained in the reforming raw material can be partially oxidized. Because the water vapor reforming reaction of hydrocarbon fuel is generally endothermic, heat is required to promote the reaction. Also, because the catalyst to be filled in the reformer has a predetermined activating temperature, the temperature of the catalyst must be at a temperature within the predetermined activating temperature range. The reformer thus requires heat, and in this aspect of the present invention, the heat required for the reforming reaction and for maintaining the catalyst at a temperature within its activating temperature range can be obtained by supplying an oxygen-containing gas and partially oxidizing a portion of the hydrocarbon fuel.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention which includes a first oxygen-containing gas supplier, the first oxygen-containing gas supplier can be configured to mix the vaporized reforming raw material and the oxygen-containing gas by swirling. In this manner, the raw material gas becomes a homogeneous mixture of vaporized reforming raw material and supplied oxygen-containing gas. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention which has a first oxygen-containing gas supplier, the first oxygen-containing gas supplier can be formed to mix the oxygen-containing gas to the vaporized reforming raw material by injecting the oxygen-containing gas in a direction perpendicular to the flow of the vaporized reforming raw material. In this manner, the reforming raw material and the oxygen-containing gas can be uniformly mixed. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the first oxygen-containing gas supplier can further comprise a supply pipe approximately in the middle of and parallel to the flow of the vaporized reforming raw material, wherein the oxygen-containing gas is injected and mixed from the external surface of the supply pipe in a direction perpendicular to the flow.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention which has a first oxygen-containing gas supplier, the reforming section can further be divided into at least two sides, front and rear, with an oxygen-containing gas supplier for supplying the oxygen-containing gas at the outer area around the entrance of the rear side. In this manner, by partially oxidizing a portion of hydrocarbon fuel contained in the reforming raw material at the rear side of the reforming section, the heat required for the reaction at the rear side and for maintaining the temperature within a temperature range where the catalyst at the rear side is activated can be obtained. Furthermore, in accordance with an aspect of the fuel reformer for mounting on a vehicle according to the present invention which has a first oxygen-containing gas supplier, the reforming section can be formed to perform the reforming reaction as well as performing partial oxidation reaction for partially oxidizing a portion of hydrocarbon fuel using oxygen-containing gas supplied by the first oxygen-containing gas supplier. In this manner, the reforming reaction can be performed with a supply of heat required for the reforming reaction and for maintaining the temperature within a temperature range where the catalyst is activated. Thus, the reformer can be simplified compared to a reformer having a separate section for supplying heat required for the reforming reaction and for maintaining the temperature within an activation temperature range of the catalyst, and the size of the reformer can be reduced.
In an aspect of the fuel reformer for mounting on a vehicle according to the present invention which has a first oxygen-containing gas supplier, the fuel reformer can further comprise a raw material gas temperature detector for detecting the temperature of the raw material gas and a second vaporization control means for controlling the operation of the vaporization section so that the temperature of the raw material gas detected by the detector is set at a target temperature preset for the raw material gas. In this manner, the raw material gas can be controlled to be at a target temperature. The target temperature is preset depending on several factors including, but not limited to, the type of catalysts used at the reforming section, the reforming reaction performed at the reforming section, the type of reforming raw material used by the fuel reformer, and the operating condition of the fuel reformer. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the second vaporization control means can be configured to control the supply amount of the oxygen-containing gas by the first oxygen-containing gas supplier.
In an aspect of the fuel reformer for mounting on a vehicle according to the present invention which has a first oxygen-containing gas supplier, the fuel reformer can further comprise a second oxygen-containing gas supplier for supplying oxygen-containing gas to the reformed gas, a reformed gas temperature detector for detecting the temperature of the reformed gas, and a gas supply amount control means for controlling the amount of oxygen-containing gas supplied by the second oxygen-containing gas supplier based on the detected temperature of the reformed gas. In this manner, reduction of carbon monoxide concentration within the reformed gas at the carbon monoxide reducing section can be efficiently performed. In this aspect of the reformer for mounting on a vehicle according to the present invention, the gas supply amount control means can be configured to control the supply amount of the oxygen-containing gas by the first oxygen-containing gas based on the temperature detected by the reformed gas temperature detector.
According to this aspect of the fuel reformer for mounting on a vehicle according to the present invention which has a second oxygen-containing gas supplier, the second oxygen-containing gas supplier can be configured to supply the oxygen-containing gas by injecting it in a direction perpendicular to the flow of the reformed gas. In this manner, the oxygen-containing gas can be supplied uniformly to the reformed gas. In this aspect of the present invention, the second oxygen-containing gas supplier can be provided with a supply pipe approximately in the middle of and along the flow of the reformed gas, with the supply pipe supplying the oxygen-containing gas by injecting it in a direction perpendicular to the flow from the outer surface of the supply pipe.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming section can be provided with an insulation layer at its outer edge. In this manner, the heat does not escape outside and the heat loss can be reduced. According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming section can be filled with a monolithic catalyst formed by carrying catalysts on a monolith carrier. Because a monolithic catalyst is formed by carrying catalysts on a honeycomb shaped carrier having various types of cross sections, it does not suffer in having spaces in an upper portion when the reforming section is horizontally placed, a problem which occurs in catalysts carried on pellets. Moreover, because it allows for more uniform gas flow, all of the catalysts can be more uniformly used, improving the reforming efficiency. In an aspect of a fuel reformer for mounting on a vehicle according to the present invention with a reforming section having an insulation layer on its outer edge and filled with a monolithic catalyst, the insulation layer can be formed by blocking the entrance and/or exit section of the cell positioned at the outer edge of the monolithic catalyst. In this manner, the construction and assembly of the insulation layer can be simplified. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention having the reforming section filled with monolithic catalyst, the reforming section can be constructed by filling the reforming section with a plurality of catalysts, formed by dividing the monolithic catalyst. In this manner, gas flow is disturbed between the divided monolithic catalysts, resulting in more uniform gas flow and promotion of contact between the unreacted gas and the catalyst, thus improving the reforming efficiency. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention having reforming section filled with monolithic catalyst, the reforming section can be constructed in an approximately cylindrical shape. In this manner, the raw material gas can flow more uniformly, improving the reforming efficiency.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming section can further comprise a liquid collecting section near the flow entrance for the raw material gas. In this manner, even when a portion of reforming raw material etc. forming the raw material gas is liquefied, the liquid can be accumulated at the liquid collecting section. As a result, performance reduction of the catalyst at the reforming section due to liquefied reforming raw material etc. can be prevented. In an aspect of the fuel reformer for mounting on a vehicle according to the present invention having the reforming section divided into two sides, the reforming section can further comprise another liquid collecting section near the flow entrance of the rear side. In this manner, even when a portion of reforming raw material etc. forming the gas flowing into the rear side is liquefied, the liquefied gas can be accumulated at the liquid collecting section. As a result, performance degradation of the catalyst in the rear side of the reforming section due to liquefied reforming raw material can be prevented. In another aspect of the fuel reformer for mounting on a vehicle according to the present invention having reforming section filled with a plurality of divided monolithic catalysts, the reforming section can further comprise liquid collecting sections between the divided monolithic catalysts filling the reforming section. In this manner, even when a portion of reforming raw material etc. forming the raw material gas is liquefied in the reforming section, the liquid can be accumulated in the liquid collecting section. As a result, performance degradation of the monolithic catalysts at the rear side due to the liquefied reforming raw material can be prevented. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the liquid collecting section can be constructed as a container that holds the monolithic catalysts. In this manner, the monolithic catalyst can be held and sliding of the monolithic catalyst due to the vehicle running etc. can be prevented. In these aspects of the fuel reformer for mounting on a vehicle according to the present invention having liquid collecting sections, the liquid collecting section can be constructed as a container having a concave channel formed at the flow path of the raw material gas in the reforming section. In an aspect of the fuel reformer for mounting on a vehicle according to the present invention in which the monolithic catalyst is divided into a plurality of monolithic catalysts to fill the reforming section, the liquid collecting section can comprise a convex channel formed inside the case filled with the monolithic catalysts.
According to another aspect of the fuel reformer for mounting on a vehicle of the present invention, the carbon monoxide reducing section can further be provided with a liquid collecting section near the flow entrance of the reformed gas. In this manner, even when reforming raw material etc. which forms a portion of unreacted raw material gas is liquefied, the liquefied gas can be collected at the liquid collecting section. As a result, performance degradation of the catalyst at the carbon monoxide reducing section due to liquefied reforming raw material etc. can be prevented. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the liquid collecting section can be provided with a concave channel formed at the flow path of the reformed gas in the carbon monoxide reducing section.
In this aspect of the fuel reformer for mounting on a vehicle according to the present invention which includes a liquid collecting section, the liquid collecting section can be constructed to have a liquid pool for collecting liquid integrated with the case. In this manner, the number of assembly steps can be reduced. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the liquid pool can be formed by pressing or spinning during the formation of the case.
According to another aspect of the fuel reformer for mounting on a vehicle of the present invention, the reforming section can further comprise a raw material gas heater near the flow entrance of the raw material gas for heating the raw material gas. In this manner, catalysts for reforming reaction can be quickly heated at the time of start-up to their activation temperature and the reformer can quickly be brought to its steady operation state. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming section can be divided into at least two sides, front and rear, and can comprise an intermediate gas heater provided between the front and rear sides for heating the gas from the front side. In this manner, heat required for the reaction at the rear side can be supplied. In these aspects of the fuel reformer for mounting on a vehicle of the present invention, the raw material gas heater and/or intermediate gas heater can be configured to partially oxidize a portion of the hydrocarbon fuel within the raw material gas. In this manner, heat can be obtained without using other fuel, and, as a result, the apparatus can be simplified and the size of the apparatus can be reduced.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the fuel reformer can further comprise a heater for heating the carbon monoxide reducing section. In this manner, the carbon monoxide reducing section can quickly be heated at the time of start-up. In this aspect of the fuel reformer for mounting on a vehicle of the present invention, the heater can be configured to include an igniter for combusting hydrogen contained within the reformed gas, and to heat the carbon monoxide reducing section by the heat generated by the hydrogen combustion. In this manner, heat can be obtained without other fuel. As a result, even when the fuel reformer is configured to quickly heat the carbon monoxide reducing section at the time of start-up, the device can be simplified, while being reduced in size.
According to another aspect of the fuel reformer for mounting on a vehicle of the present invention, the reforming section can further comprise a dividing section for dividing the reforming section into two sides, front and rear, and a dividing section gas supplier for supplying oxygen-containing gas to the dividing section. In this manner, the rear side of the reforming section can also be heated at the time of start-up, as well as the front side. In this aspect of the fuel reformer for mounting on a vehicle of the present invention, the dividing section gas supplier can be configured to disturb the gas flow at the dividing section by supplying the oxygen-containing gas. In this manner, the oxygen-containing gas can be more uniformly distributed. In the aspect of the fuel reformer for mounting on a vehicle of the present invention having a dividing section gas supplier, the dividing section can further include a bending section for bending in a predetermined angle and the dividing section gas supplier can be provided in contact with the inner surface of the outer wall of the bending section. In this manner, gas can be prevented from flowing nonuniformly through the bending section and can flow more uniformly.
In this aspect of the fuel reformer for mounting on a vehicle of the present invention in which the dividing section is provided with a bending section, the dividing section gas supplier can further comprise a plurality of nozzles for injecting the oxygen-containing gas at a predetermined angle with respect to the gas flow in the bending section. In this manner, the oxygen-containing gas can be supplied more uniformly. In this aspect of the fuel reformer for mounting on a vehicle of the present invention, the dividing section gas supplier can be formed by processing a tube or by forming a hollow structure using a pressing or welding process.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention in which the dividing section is provided with a bending section, the dividing section can further comprise a flow adjusting device for adjusting the gas flow direction within the bending section. In this manner, the gas flow direction at the bending section can be adjusted and the gas can be more uniformly supplied to the rear side. In this aspect of the fuel reformer for mounting on a vehicle of the present invention, the flow adjusting device can be a channel formed in convex shape at the interior of the bending section.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the fuel reformer can further comprise heating means for heating the reforming section which is placed to wrap the reforming section. The reforming section can thus be heated. By configuring the fuel reformer so that the reforming section is heated at its start-up, the fuel reformer can quickly be brought to its steady operation state, and the start-up performance can be improved.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention which includes a heater, the reforming section can have a double layered structure comprising an inner casing and an outer casing, and the heater can be placed in the space between the inner and outer casings of the double layered structure.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention which includes a heater, the heater can comprise a heating element for generating heat by oxidation and an oxidizing gas supplier for supplying oxidizing gas to the heating element so that the heating element can oxidize. In this manner, the reforming section can be heated by merely supplying oxidizing gas.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention in which the heater includes a heating element, the heater can further comprise start-up control means for controlling the oxidizing gas supplier so that oxidizing gas is supplied to the heating element at the time of start-up of the reforming section. In this manner, the reforming section can quickly be brought to its steady operation state.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention in which the heater includes a heating element, the heater can further comprise a reforming temperature detecting sensor for detecting the temperature of the reforming section and oxidation control means for controlling the supply of the oxidizing gas by the oxidizing gas supplier based on the detected temperature. In this manner, heating of the reforming section by the heater can be controlled based on the temperature of the reforming section.
Alternatively, in the aspect of the fuel reformer for mounting on a vehicle according to the present invention in which the heater includes a heating element, the heater can further comprise a deoxidizing gas supplier which can supply deoxidizing gas to the heating element for deoxidizing the heating element. In this manner, the oxidation and deoxidation of the heating element can be repeated. In other words, heating of the reformer by oxidation of the heating element can be repeated.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention in which the heater includes a deoxidizing gas supplier, the heater can further comprise termination control means for controlling the deoxidizing gas supplier at the termination of the operation of the reformer so that the deoxidizing gas is supplied to the heating element at the termination of the operation of the reforming section. In this manner, the heating element can be deoxidized when the operation of the reforming section is terminated. In other words, the heating element can be deoxidized so that the heating element is ready to be oxidized at the next start-up of the reforming section. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the deoxidizing gas supplier can be supplying means for supplying, as the deoxidizing gas, fuel gas formed by reforming raw material gas remaining in the vaporization section and unreacted raw material gas remaining in the reforming section when the termination of the operation of the reforming section is instructed. In this manner, the fuel gas formed by reforming the unreacted raw material gas can be processed and used effectively.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention including a deoxidizing gas supplier, the heater can further comprise a heating element temperature detecting sensor for detecting the temperature of the heating element and deoxidation control means for controlling the supply of the deoxidizing gas by the deoxidizing gas supplier based on the detected temperature. In this manner, because the deoxidation reaction of the heating element is generally either exothermic or endothermic, by controlling the supply of deoxidizing gas based on the temperature of the heating element, the temperature of reforming means can be adjusted. Thus, by configuring the reforming section to adjust to a temperature where the reforming section can effectively operate, unreacted raw material gas in the reforming section can be reformed.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the vaporization section, the reforming section, and the carbon monoxide reducing section can each be constructed as a separate unit with a connector for connecting to the other units. In this manner, ease of maintenance can be improved. It also enables simple exchange of each of the sections. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the connector can be constructed from a flange and a V-shaped band for fastening the flange. Because fastening by a V-shaped band has a small heat capacity in general, heat loss can be reduced. Moreover, it allows more uniform sealing and the size of the device can be reduced.
In the aspect of the fuel reformer for mounting on a vehicle according to the present invention having each of the vaporization section, reforming section, and carbon monoxide reducing section constructed as a separate unit, the connector can include a member holding structure for holding the members at the time of connection. In this manner, the members can be held during the connection of the separate units, and the assembly can be simplified. Here, xe2x80x9cmembersxe2x80x9d include not only the members that are not included in each of the units, but also the members included in each of the units such as, for example, a gasket.
In this aspect of the fuel reformer for mounting on a vehicle according to the present invention where the vaporization, reforming, and carbon monoxide reducing sections are each provided as a separate unit, at least one of the unitized vaporization, reforming, and carbon monoxide sections can be constructed from a plurality of parts, each of which is provided as a separate unit. In this manner, assembly of a plurality of separate units can be simplified and the operational ease during manufacturing can be improved. In this aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming section can comprise a flow rate unifying section for making the flow rate of the raw material gas uniform, a raw material gas heating section for heating the raw material gas, and a catalyst section having a catalyst for reforming supplied raw material gas, each of which is separately provided as a unit.
According to another aspect of the fuel reformer for mounting on a vehicle according to the present invention, the reforming raw material can be a liquid mixture of water and methanol and the raw material gas can be a mixture gas of the vaporized reforming raw material and oxygen-containing gas.